Prescribing Glasses For Pseudophakia

Indications

All patients should undergo refraction following cataract surgery to assess the postoperative refractive status of the eye. Ideally, this should be performed within 4 weeks after surgery, once postoperative inflammation and swelling have resolved. The primary goal is to evaluate the refractive outcome of the procedure and identify any residual refractive error that may require correction with glasses or other interventions.

Indications for Prescribing Glasses in Pseudophakic Patients

Residual refractive error

Achieving emmetropia is not always possible—or even the intended goal—after cataract surgery. Some patients are purposefully left mildly myopic to enhance near or intermediate vision. Others with astigmatism may choose a more affordable non-toric IOL, which can result in residual astigmatism requiring correction. In such cases, glasses can effectively address these residual refractive errors, improving overall visual outcomes.

Intermediate and near vision

Standard monofocal IOLs are typically selected to correct distance vision. Postoperatively, these patients will likely require glasses for intermediate and near tasks.

Multifocal or extended depth of focus intraocular lens

These specialty IOLs are designed to enhance independence from glasses after cataract surgery. For example, patients with a distance EDOF IOL typically have good distance vision and functional intermediate vision (eg, for computer use). However, they may still require glasses for prolonged reading or detailed tasks to reduce eye strain and optimize visual performance.[13]

• Changing vision: Even pseudophakic patients may experience changes in vision over time due to unrelated ocular conditions or natural aging. Regular eye examinations and timely updates to spectacle prescriptions help maintain optimal visual function.

• Monocular patients: Patients with functional vision in only one eye should wear glasses, even if corrective lenses are not necessary for vision.[14] Glasses made from shatterproof materials, such as polycarbonate or Trivex, are strongly recommended to protect the remaining functional eye from trauma. The prescription is usually balanced to minimize unwanted magnification or minification of the eye, preventing an asymmetric facial appearance.

Contraindications

Refraction and prescription of glasses in pseudophakic patients are not associated with any absolute contraindications. However, several factors can complicate the process or reduce the accuracy of refraction, which will be discussed in this section..

Early Postoperative Period

As part of the normal healing process after cataract surgery, the eye may experience various fluctuations that could result in an unstable refraction. Contributing factors such as corneal edema, intraocular inflammation, and macular edema can contribute to unstable or inaccurate refraction. Generally, most refractionists wait from 4 to 6 weeks after surgery to allow the eye to stabilize before performing a definitive refraction. More complex cases may require additional time. Even after complete healing, multiple studies indicate that test-retest refraction measurements can vary by up to 0.50 diopters in 95% of cases.[15]

Secondary Cataract (Posterior Capsular Opacification)

During routine phacoemulsification cataract surgery, once the cataract is removed, an IOL is implanted within the native capsular bag to maintain proper positioning. Over time, this capsular bag can develop posterior capsular opacification (PCO), which may become visually significant. PCO is believed to result from the proliferation of residual lens epithelial cells within the capsule, leading to light scatter and diminished visual quality.[16] 

With modern foldable IOLs, approximately 12% to 31% of patients develop visually significant PCO, which typically occurs several months to years after cataract surgery. Patients with significant PCO should undergo a refraction and some form of glare testing (such as brightness acuity test [BAT]), and a slit lamp examination. If PCO is confirmed, treatment with a YAG laser capsulotomy is indicated. Once a clear visual axis is restored, a more accurate refraction can be performed. Please see StatPearls' companion resource, "Tests for Potential Vision," for more information.

Ocular Surface Disease

Although not exclusive to pseudophakic patients, cataract surgery can exacerbate preexisting ocular surface disease. Conditions such as dry eye or irregularities in the tear film may cause fluctuations in vision and reduce the accuracy of refraction. Additionally, dry eye can compromise the reliability of biometric measurements, particularly keratometry.[17] To reduce the risk of infection, impaired wound healing, and suboptimal visual outcomes, the ocular surface should be optimized before surgery.[18] Neuropathic dry eye is more prevalent following cataract surgery, with approximately one-third of patients reporting symptoms 6 months after their surgery.[19] 

Higher Order Aberrations

Even when refraction yields 20/20 (6/6) visual acuity, some patients may report persistent blur, ghosting, or monocular diplopia and express dissatisfaction with their visual outcome. These symptoms are often attributed to higher-order aberrations, commonly caused by ocular surface disease or corneal irregularities. In such cases, corneal topography, aberrometry, and over-refraction with a rigid gas-permeable contact lens may help identify the underlying issue. Please see StatPearls' companion resource, "Tests for Potential Vision," for more information.

Retinal or Optic Nerve Pathology

Underlying ocular diseases—such as diabetic retinopathy, epiretinal membranes, macular degeneration, glaucoma, and other conditions—can significantly affect best-corrected visual acuity. Patients with these preexisting pathologies should be counseled to maintain realistic expectations regarding their visual potential after cataract surgery. Despite appropriate postoperative correction with glasses, their best-corrected visual acuity may remain limited due to the underlying retinal or optic nerve disease.

Refractive surgery enhancement

Another reason to avoid glasses postoperatively is the option of refractive surgery enhancement. Many patients are eligible for this procedure after undergoing IOL implantation. Typically, these patients have minor residual refractive errors and adequate corneal thickness, allowing them to undergo a small additional corneal treatment. Following complete healing from cataract surgery, these “touch-ups” may help patients achieve greater independence from glasses.[20]

Equipment

Several pieces of equipment may be required to perform refraction in a pseudophakic patient. The initial step in identifying postoperative refractive error is typically autorefraction.[21] An autorefractor offers the refractionist an initial estimate of the patient’s refractive error, which is subsequently refined through subjective refraction. The device operates by projecting infrared light into the eye and measuring the changes in the light as it reflects off the retina. During this process, the patient views an image that shifts in and out of focus, allowing the device to approximate the necessary correction. Most modern autorefractors also include keratometry, which measures the anterior corneal curvature and assesses the magnitude and axis of corneal astigmatism. This is particularly important for pseudophakic patients who may have preexisting or surgically induced corneal astigmatism. Please see StatPearls' companion resources, "Autorefractors" and "Keratometer," for more information.

Using the preliminary prescription from the autorefractor, further refinement can be performed with either a manual or automatic phoropter. A phoropter is a device that enables the refractionist to quickly and smoothly switch between lenses for precise, customized adjustments to a patient’s prescription. Manifest refraction is a manual, subjective refraction performed on a non-cycloplegic eye.[22] 

Cycloplegic agents, such as cyclopentolate or tropicamide, temporarily paralyze the ciliary body by blocking acetylcholine receptors, thus impeding accommodation.[23] Although the magnitude of accommodation possible in pseudophakia is a matter of controversy, some evidence suggests that ciliary body contraction may be capable of inducing axial displacement of IOLs.[23] Thus, cycloplegic refraction may still have a role in pseudophakia.[24][25] Manifest refraction is a technically demanding clinical skill that requires an experienced refractionist to ensure an accurate and reliable prescription. 

Retinoscopy is another method of objective refraction. Using a retinoscope, the clinician assesses refractive error by analyzing the reflection of light from the retina. This technique is particularly useful for nonverbal patients or those unable to participate in a subjective examination. While the detailed steps of retinoscopy are beyond the scope of this overview, they are available in StatPearls' companion resource, "Objective Refraction Technique: Retinoscopy."

Visual acuity charts, such as Snellen or LogMAR charts, are essential tools for measuring visual acuity, evaluating overall vision, and refining manifest refraction.

BAT is another valuable tool for determining the presence of pseudophakic corneal edema, corneal endothelial guttate, POC, or other media opacities that can affect refraction results and cause glare.[26]

Corneal topography is a diagnostic tool that creates a 3-dimensional (3D) map of the corneal surface. Manual keratometry measures the curvature of the cornea. Both instruments are particularly useful in determining the starting point for refraction in cases of irregular or high astigmatism. Please see StatPearls' companion resource, "Corneal Topography," for more information.

Aberrometry is used to analyze wavefront aberrations in the eye before, during, and after surgery to assist with IOL selection and placement, as well as to evaluate patient concerns regarding their refractive outcomes.[27] 

Personnel

In the United States, prescribing glasses for pseudophakic patients typically involves a collaborative effort among various eye care professionals. Ophthalmologists, optometrists, technicians, and opticians each play distinct roles in the care of these patients after surgery. Although the education, experience, and responsibilities of these professionals may differ, all share the common goal of achieving the best possible postoperative visual outcome for the patient.

In general, nonsurgical management, such as spectacle measurements and contact lens fitting, involves optometrists, ophthalmologists, technicians, and/or opticians. Surgical interventions, however, are performed exclusively by ophthalmologists. Opticians are trained to design, fit, and dispense eyeglasses and contact lenses based on prescriptions provided by ophthalmologists or optometrists. Please see StatPearls' companion resource, "Prescribing Glasses for Aphakia," for more information.

Poor communication or subtle interprofessional differences regarding refraction can lead to suboptimal visual outcomes. A key nuance involves the way ophthalmologists and optometrists write prescriptions—ophthalmologists traditionally use positive cylinder notation, while optometrists record prescriptions in negative cylinder power. Understanding how to accurately convert between these formats is essential to prevent refractive errors.

Transposing a Prescription

Transposing a prescription involves the following steps:

1. Mathematically, the cylindrical power should be added to the spherical power.
2. The sign of the cylindrical power is then reversed.
3. The axis is adjusted by 90 degrees.

Examples

• Positive to negative cylinder (+ to − cylinder): +1.00 + 1.00 × 090 becomes +2.00 − 1.00 × 180.
• Negative to positive cylinder (− to + cylinder): −2.00 − 1.50 × 180 becomes −3.50 + 1.50 × 090.

With the advent of online spectacle vendors, it is important for patients to understand that optimal visual performance depends on properly measured and fitted spectacle lenses. Accurate measurements of pupillary distance, fitting height, vertex distance, and pantoscopic tilt are essential to ensure comfortable and clear vision.[28] 

Technique or Treatment

The specific steps of manifest refraction are beyond the scope of this overview but can be found in the "Subjective Refraction Techniques."

Clinical Significance

Multiple studies have demonstrated that cataract surgery improves visual function and enhances patient quality of life. Benefits include a reduced risk of falls, improved postural stability and mobility, enhanced cognition, better sleep quality, and lower rates of depression following cataract surgery.[29][30][31][32] However, these important improvements may be diminished or negated if residual refractive errors remain uncorrected.

Furthermore, wearing glasses after cataract surgery is a common practice. Even in cases where bilateral emmetropia is achieved, many pseudophakic patients continue to use varifocal glasses more than 50% of the time.[9] As such, achieving the most accurate postoperative refraction is essential. Although contact lenses or refractive surgery may be suitable for select patients, the majority still rely on glasses to achieve their best possible visual outcome.

Conclusion

Cataract surgery ranks among the most commonly performed procedures in the United States, with demand expected to rise as the population ages. Prescribing glasses for pseudophakic patients is often essential to achieve optimal postoperative vision. This process is most effective when ophthalmologists collaborate closely with optometrists, technicians, and opticians.

Enhancing Healthcare Team Outcomes

Achieving optimal postoperative vision in pseudophakic patients requires close collaboration among eye care professionals. This includes providing comprehensive patient education, managing expectations effectively, performing technically proficient surgery, and ensuring appropriate postoperative care, including accurate refraction and prescription of spectacles. A strategic, evidence-based approach is crucial for optimizing treatment outcomes and minimizing complications. Ethical considerations, including informed consent and respect for patient autonomy, should guide all clinical decisions and practices. Each healthcare professional should understand their specific responsibilities and contribute their unique expertise to the patient’s care plan, supporting a comprehensive multidisciplinary approach.

Effective interprofessional communication among healthcare providers is crucial for seamless information exchange and collaborative decision-making among healthcare team members. Coordinated care ensures that the patient’s journey—from diagnosis through treatment and follow-up—is efficiently managed, reducing the risk of errors and enhancing patient safety. By upholding the principles of clinical skill, strategic planning, ethical practice, role clarity, interprofessional collaboration, and care coordination, healthcare professionals can deliver patient-centered care that improves outcomes and strengthens team performance in the care of pseudophakic patients requiring glasses.